What is the difference between nervous and hormonal coordination?

Nervous coordination uses fast electrical impulses carried by neurones, giving a quick, short-lived and precisely targeted response. Hormonal coordination uses chemical hormones carried more slowly in the blood, giving a slower but longer-lasting response that can affect many organs at once.

How is blood glucose controlled?

The pancreas monitors blood glucose. When it is too high, the pancreas releases insulin, which makes cells take up glucose and the liver store it as glycogen, lowering the level. When it is too low, the pancreas releases glucagon, which makes the liver break glycogen back into glucose, raising the level. This is negative feedback.

What is the difference between type 1 and type 2 diabetes?

In type 1 diabetes the pancreas does not produce enough insulin, so it is treated with insulin injections. In type 2 diabetes the body cells stop responding properly to insulin; it is linked to obesity and usually controlled with a carbohydrate-controlled diet, exercise and weight loss, sometimes with medication.

Homeostasis is the regulation of the internal conditions of the body to keep them stable, such as blood glucose concentration, temperature and water balance. It works by negative feedback: if a level moves away from normal, a response is triggered that brings it back towards the set point.

EnglandCombined Science

Edexcel GCSE Combined Science CB7 Animal coordination, control and homeostasis: a complete overview of hormones, blood glucose and diabetes

Q: What does Edexcel Combined Science CB7 cover?

CB7 covers the endocrine system and how hormones act as chemical messengers carried in the blood, the principle of homeostasis and negative feedback, the control of blood glucose concentration by insulin and glucagon from the pancreas, and the causes and treatments of type 1 and type 2 diabetes.

A deep-dive Edexcel GCSE Combined Science guide to Topic 7 (CB7) Animal coordination, control and homeostasis. Covers the endocrine system and hormones, homeostasis and negative feedback, the control of blood glucose by insulin and glucagon, and type 1 and type 2 diabetes, with the exam patterns Edexcel repeats.

Generated by Claude Opus 4.812 min readCB7Updated 2026-06-02

Reviewed by: AI editorial process; not yet individually human-reviewed

Jump to a section

What CB7 actually demands
The endocrine system
Homeostasis and negative feedback
Controlling blood glucose
Diabetes
How CB7 is examined
Check your knowledge

What CB7 actually demands

Animal coordination, control and homeostasis covers how hormones run slower, longer-lasting control in the body, with blood glucose control as the central example. The examiners reward the full insulin and glucagon negative-feedback answer, and a clear comparison of type 1 and type 2 diabetes.

This guide walks through the topic and ties together the matching dot-point page, which has its own practice questions.

The endocrine system

The endocrine system is a set of glands that release hormones (chemical messengers) into the blood. Compared with the nervous system, hormonal responses are slower and longer-lasting. Key glands include the pancreas, thyroid, adrenal glands and reproductive organs, with the pituitary as the master gland.

Homeostasis and negative feedback

Homeostasis keeps internal conditions stable using negative feedback: when a level rises or falls away from normal, a response brings it back. Blood glucose, temperature and water are all controlled this way.

Controlling blood glucose

The pancreas controls blood glucose:

Too high: release insulin, which makes cells take up glucose and the liver store it as glycogen. Glucose falls.
Too low: release glucagon, which makes the liver turn glycogen back into glucose. Glucose rises.

Diabetes

Type 1 diabetes: the pancreas makes too little insulin; treated by insulin injections. Type 2 diabetes: the cells stop responding to insulin; linked to obesity and treated with diet, exercise and weight loss.

How CB7 is examined

Negative feedback. The full insulin and glucagon answer for controlling blood glucose.
Comparison. Distinguishing type 1 and type 2 diabetes by cause and treatment.
Vocabulary. Not confusing insulin with glucagon, or glucagon with glycogen.
Application. Predicting which hormone is released for a given change in glucose.

Check your knowledge

A mix of recall and application questions covering CB7. Attempt them under timed conditions, then check against the solutions.

Define a hormone. (2 marks)
Name the gland that controls blood glucose. (1 mark)
State what insulin does to blood glucose. (1 mark)
State what glucagon does to blood glucose. (1 mark)
Name the carbohydrate that glucose is stored as in the liver. (1 mark)
State the cause of type 1 diabetes. (1 mark)
State a treatment for type 2 diabetes. (1 mark)
Define homeostasis. (2 marks)

Sources & how we know this

Edexcel GCSE (9-1) Combined Science (1SC0) specification — Pearson (2016)